Capacitors, such as double-layer capacitors, are also used in applications with high output requirements, because they can be implemented with high capacitances with simultaneously very low ESR. When used as temporary energy storage, for example, double-layer capacitors must emit or absorb, within relatively short periods of time of a few seconds or less, high currents and, associated with this, high energy. The operating voltages of double-layer capacitors generally amount to only a few volts. However, because applications usually require significantly higher voltages, multiple double-layer capacitors are frequently connected in series to form a capacitor battery. Because of the large number of individual capacitors, this means that constructing a capacitor battery is often very cost-intensive. For this reason, capacitors with the highest possible operating voltages are in demand. The later that critical corrosion currents are reached during charging of the capacitor, the higher its operating voltage. A high operating voltage requires a higher output density and energy density of the capacitor. The rated voltage of a capacitor is upwardly limited by the difference between the corrosion potentials of the capacitor electrodes and the electrolyte. If an electrode is at a potential within the corrosion range, electrochemical reactions can disadvantageously lead to corrosion of the electrodes or to disintegration of the electrodes, a process in which gas development can occur, significantly reducing the serviceable life of the capacitor. To avoid this, capacitors are generally used only at operating voltages at which the resulting individual electrode potentials remain outside the corrosion potential.